No. 104.] 59 



plant. These variations make it difficult to accurately describe the 

 species and to satisfactorily identify them from the published descrip- 

 tions. Some of them, by reviving under the influence of moisture 

 and by the tenacity of their substance, indicate an affinity with tlie 

 genus Panus and its allies. Some of the larger stout-stemmed speciis 

 occasionally have the stem nearly or quite central in which case thev 

 might be taken for species of Tricholoma, though their lignatilc in- 

 stead of terrestrial habitat would bean indication of their real affinity, 

 but not a wholly reliable one, since some species of Tricholoma grow i 

 on wood. By their white spores they are separated from the otherwise 

 similar Claudopodes and Crepidoti. Two species, P. saj)f(lu.<i and 

 P. euosmus have pale lilac-tinted spores, but these can scarcely justifv 

 the removal of these plants to any genus having colored spores, since 

 they would harmonize no better there than liere. Indeed there is 

 room for doubt if either of these supposed species is more than a 

 variety of P. ostreatus. Several species have valuable esculent cpiali- 

 ties. Fries has divided the genus into three sections, which for 

 convenience we have adopted in the arrangement of our Xew York 

 Pleuroti. He names them respectively, Excentrici, Dimidiati and 

 Resupixati. 



Synopsis of the Species. 



Stem eccentric pileus entire or marginate behind 1 



Stem none or short, pileus sessile or not marginate behind 7 



1. Lamella; adnate or emarginate, not decurrent 2 



1. Lamellae distinctly decurrent 4 



2. Lamellae white 3 



2. Lamellae yellow P. sulph uremcleit. 



3. Odor farinaceous, spores elliptical P. Ugiititilis. 



3. Odor not farinaceous, spores globose P. ulmarius. 



4. Pileus slightl\* areolate P. subanolaius. 



4. Pileus not areolate 5 



5. Spores dull lilac P- sainduf. 



5. Spores white 6 



6. Lamellae anastomosing at the base P- ostreatus. 



6. Lamellae distinct at the base P- salignus. 



7. Pileus never resupinate, generally with a short lateral stem or stem- 

 like base 8 



7. Pileus at first resupinate, generally sessile 11 



8. Pileus viscid when young or moist P- sirotinus. 



8. Pileus not viscid ^ 



9. Lamellte gray, subdistant, stem not compressed P- tninulua. 



9. Lamellae wliite, crowded, stem compressed 10 



10. Plant growing on the ground P ^P^f^' "^"/"••'• 



10. Plant growing on decaying wood P- />»^*^'"^< * 



11. Pileus white '"- 



11. Pileus not white • ^"^ 



12. Pileus one inch or more long "• porrtgcns. 



12. Pileus small, less than one inch long or broad P- stptii-un. 



13. Lamelhe white or yellowish P.atrocitrHl. u». 



13. Lamelhe cinereous, livid-brown or blackish • >■* 



14. Pileus even or slightly striate on the margin P- atro^fUit'i^. 



14. Pileusi plicate-striate, black W .'■ ' ' ' 



14. Pileus striate, cinereous or livid-brown I . sti'iittu. ai. 



Pileus entire or with a thin margin on unr .^idt; .^tc/u distinct, acin- 

 tric or lateral. 



